Vacuum drying in battery cell production

Interview with the expert

Stefan Betz

Product Manager Heat Technology

What advantages does vacuum technology offer in drying processes?

According to the vapor pressure-temperature curve, reduced air pressure also reduces the boiling point of liquid mixtures. These then evaporate at much lower temperatures and can be actively sucked out of a recipient. Therefore, sensitive products do not need to be heated as much in a vacuum to achieve the same drying performance. All air and vapor pockets in the product are removed and re-condensation after the drying process is reliably prevented. This makes vacuum drying the perfect solution wherever moisture has to be carefully removed from sensitive materials without leaving any residue and in a process-safe manner.

How can vacuum drying be used in battery manufacturing?

Vacuum drying is the final step in electrode production. To ensure that the batteries later offer the required performance and longevity, the coated coils must be dried in the most efficient way possible. In the process, even the smallest residues of moisture and solvents are removed from them. Vacuum dryers with circulating air tempering realize this process particularly efficiently. After complete drying, the coils are transferred to cell assembly, where they are further processed under controlled drying room conditions – dew point - 60°C, for example.

How does vacuum drying optimize the production of lithium-ion batteries?

Currently, there are no established or standardized standard processes for vacuum drying in battery manufacturing. That’s why it’s exciting to support research manufacturing and help develop these standards. We do this with our customized and process-optimized vacuum drying solutions for efficient and safe battery production. We integrate these into the production line as required. Since flammable solvents are used in electrode production, process reliability is a particularly important aspect. To ensure this, we use our extensive experience in thermal engineering.

Dry safely faster
Optimize process times

Short process times are important in industrial battery production. To dehumidify the temperature-sensitive battery electrodes as quickly as possible and at the same time completely and safely, we recommend particularly gentle hybrid drying systems with circulating air temperature control. The fast process with short heat-up time achieves optimum drying results and eliminates air pockets in the electrodes. This is crucial for the performance of the batteries.

Everything always under control
Safe quality due to consistent manufacturing conditions

For high battery quality, the entire manufacturing process must take place under controlled, dry environmental conditions. A crucial point here is the connection between the individual production steps. Vacuum dryers can be used as an airlock for the electrodes between the different drying rooms. Passing the coils through the airlock ensures that the low dew points of -40 to -60 ºC are not interrupted.